LOCATION DARDANELLE AR+TXEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Typic Argiudolls
TYPICAL PEDON: Dardanelle silt loam, on a smooth 1 percent slope, in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 7 inches; very dark grayish brown (10YR 3/2) silt loam; weak fine granular structure; friable; many fine roots; medium acid; abrupt smooth boundary. (5 to 10 inches thick)
A--7 to 23 inches; very dark brown (10YR 2/2) silt loam; weak fine subangular blocky structure; friable; common fine roots; common fine tubular pores; common worm channels; slightly acid; clear smooth boundary. (12 to 20 inches thick)
Bt1--23 to 28 inches; dark reddish brown (5YR 3/3) silt loam; moderate medium subangular blocky structure; friable; dark brown (7.5YR 3/2) coatings on many faces of peds; few thin distinct clay films on faces of peds; common fine roots; common fine tubular pores; few very dark brown (10YR 2/2) pockets of A material in worm channels; moderately acid; clear smooth boundary.
Bt2--28 to 35 inches; reddish brown (5YR 4/4) silty clay loam; moderate medium subangular blocky structure; firm; dark reddish brown (5YR 3/3) coatings on many faces of peds; few distinct clay films on faces of peds; few fine roots; common fine tubular pores; few very dark brown (10YR 2/2) pockets of A material in worm channels; moderately acid; clear smooth boundary.
Bt3--35 to 51 inches; reddish brown (5YR 4/4) silty clay loam; moderate medium subangular blocky structure; firm; few distinct clay films on faces of peds; few fine roots; few fine tubular pores; moderately acid; clear smooth boundary. (Combined thickness of the Bt horizon ranges from 27 to 40 inches thick.)
C1--51 to 74 inches; brown (7.5YR 5/4) very fine sandy loam; massive; friable; moderately acid; gradual smooth boundary. (10 to 30 inches thick)
C2--74 to 91 inches; brown (7.5YR 5/4) silt loam; massive; friable; common bedding planes; medium acid.
TYPE LOCATION: Pope County, Arkansas; 800' S and 1220' W of NE corner sec. 11; SW1/4NE1/4NE1/4 sec. 11, T. 6 N., R. 20 W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 44 to 70 inches. Thickness of the mollic epipedon ranges from 20 to 40 inches. Reaction ranges from moderately acid to neutral in the A and BA horizons; strongly acid to neutral in the B horizon; moderately acid to mildly alkaline in the BC horizon and strongly acid to moderately alkaline in the C horizon. In some pedons, the C horizon is calcareous.
The A horizon has hue of 10YR, value of 2 or 3, and chroma of 2 or 3, or hue of 7.5YR, value of 3, and chroma of 2, or hue of 5YR, value of 3, and chroma of 2 or 3. Texture is silt loam, loam or very fine sandy loam.
The BA horizon, where present, has hue of 10YR, value of 2 or 3, and chroma of 2 or 3, or hue 7.5YR, value of 3, and chroma of 2, or hue of 5YR, value of 3, and chroma of 2 or 3. Texture is silt loam or silty clay loam.
The Bt1 horizon has hue of 10YR, value of 3, and chroma of 2 or 3, or hue of 7.5YR, value of 3, and chroma of 2, or hue of 5YR, value of 3, and chroma of 3. Texture is silt loam or silty clay loam. The Bt2 and Bt3 horizons have hue of 5YR, value of 3, and chroma of 3 or 4, or value of 4, and chroma of 3, 4 or 6, or hue of 7.5YR, value of 4, and chroma of 2 or 4, or hue of 10YR, value of 4, and chroma of 3 or 4. Texture is silt loam or silty clay loam. Although not diagnostic, dark colored ped coatings are present in the Bt2 and Bt3 horizons of most pedons. The clay content ranges from 20 to 35 percent with less than 15 percent coarser than very fine sand. Some pedons have high chroma mottles below 30 inches.
The BC horizon, where present, has hue of 10YR, value of 4, and chroma of 3 or 4, or hue of 7.5YR, value of 4, and chroma of 2 or 4, or hue of 5YR, value of 3 or 4, and chroma of 3 or 4. Texture is silt loam or loam.
The C horizon has hue of 5YR, value of4 or 5, and chroma of 4 or 6, or hue 7.5YR, value of 4, and chroma of 4, or value of 5, and chroma of 4 or 6. Texture is silt loam, very fine sandy loam, or loam. The C horizon is stratified and often has bedding planes.
COMPETING SERIES: Caspiana, Catoosa, Deepwater, Lula, Mason, Mer Rouge and Tiptonville series. Caspiana, Deepwater, and Tiptonville soils have mollic epipedons 10 to 20 inches thick. Catoosa soils have 20 to 40 inch solums. Lula soils have mollic epipedons 10 to more than 20 inches thick; have lithic contact between 40 and 60 inches and contains chert and limestone fragment in the lower Bt horizons. Mason soils have moderately slow permeable in the Bt horizon. Mer Rouge soils have 5 to 25 percent by volume calcium carbonate concretions within 15 to 30 inches of the surface.
GEOGRAPHIC SETTING: Dardanelle soils are on level to gently undulating old natural levees in the Arkansas and Red River bottomlands. Slopes range from 0 to 3 percent. They formed in reddish brown alluvium. The climate is warm and humid with mean annual rainfall of about 48 inches and mean annual temperature of about 60 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: Gallion, Moreland, Rilla, Roellen, and Roxanna series. Gallion soils occur on slightly higher landscapes and have ochric epipedons. Moreland soils occur in slackwater areas and do not have an argillic horizon and have vertic properties. Rilla soils occur on slightly higher landscapes and have ochric epipedons. Roellen soils occur in slackwater areas have a fine control section and are poorly drained. Roxanna soils occur on younger natural levees, have a coarse-loamy control section and do not have as argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to moderate runoff; moderate permeability.
USE AND VEGETATION: Mainly in cultivated crops such as cotton, soybeans, and small grains.
DISTRIBUTION AND EXTENT: Arkansas and Red River Valleys in Arkansas, Louisiana, Oklahoma, and Texas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Crawford County, Arkansas; September,
1975.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon--zone from the surface to a depth
of 28 inches.
Argillic horizon--zone from 23 to 51 inches.
These soils were formerly mapped with the Caspiana series.